do i need a waterproof keyswitch for 90volts?

madin88

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Hi,
i have installed a 3-wire keyswitch on my bike which is part of a masterswitch circuit (richard fechter V3).
On this switch there is full battery voltage and also battery ground. Battery is 90V hot off charger.
All parts on my bike are protected against water splashes (battery in peli cases, circuit box ip65, controller ip54), except of this keyswitch. It is because i couldn't find any waterproof one at my electronic store.
In the positive wire there is a 1M Ohm resitstor which is needed for the circuit.

Now i bother about what may happen if some water get in this keyswitch (for example if i leave the bike in the rain or clean it with water).
Will it short circuit? I think water will live current at 90V or i am wrong?
Could it be possible the bike turns on?
 
Subsa said:
yes, you need

ok, thanks.
someone know any good shop where i can buy?
I find some on ebay, but they do not look like good, durable quality.
 
i'd consider using a relay instead. that is because, for example, i have a 24v relay rated for 80a with silver contacts. this way the relay could be totally sealed off from water, and the key switch could be ordinary and do the job.
So it depends on what you can find. Perhaps a car relay that turns on the radiator fan? They won''t be rated for 90v, so i'm not sure, i'm just giving ideas. What is your max. amps?
 
Matt Gruber said:
i'd consider using a relay instead. that is because, for example, i have a 24v relay rated for 80a with silver contacts. this way the relay could be totally sealed off from water, and the key switch could be ordinary and do the job.
So it depends on what you can find. Perhaps a car relay that turns on the radiator fan? They won''t be rated for 90v, so i'm not sure, i'm just giving ideas. What is your max. amps?

I already have a Mosfet relay in my electronic box. This is a good way to build a masterswitch including a precharge circuit for controller capacitors.
On this keyswitch there is nearly zero current flow (about some µA i think).
lets assume the circuit in this little keyswitch got filled with water:
I think on 90V there will easy flow some µA and this is enough to turn on the gate. Ok, it will depend on the gap between the contacts.. Anyone knows the resistance of water?

Off position: battery negative is short direct to gate of Mosfet's
On position: battery positive (90V at my circuit) is short to Mosfet's gate over precharge circuit with 1M resistor to turn on slowly the gate and charge capacitors

this is how it works

some pics

l7j8.jpg


0md5.jpg
 
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